cryptomatte masks

[kirk23]

I know we could  probably build it from layer blending or using procedural  filter    but I never had a deep understanding of a math behind it .   I just want something like this please:

I mean "criptomatte" checkbox in open dialog with option to have  just  black and white mask layers  instantly   ready to use  instead of endless  cryptomatte layers that are actually saved in exr .       Probably with some preview and checkboxes of what exact render layer or object/material mask I need from an exr.     Something painless and easy.

Something with checkboxes and preview of what you need  like resource manager :

1 denoised  beauty pass(AOV).  >>check

2>  shadows  >>> check

3. indirect illumination  >>> check

3 cryptomatte mask of  material or object 1  >>> pass

and so on

Something that we could keep in embedded/linked  doc  only  and  do actual image tweaking in  regular 8 bit image with 10 layers only . not hundreds of them.

 

Perhaps even more  elegant interface would be a special procedural mask  that would keep a link to outside exr file and allows to pic a material . object. instance , smoke piece or whatever from CG image,   just of screen,    and return just a black and white mask  without looking through hundreds of layers

Find a code of  Blender compositer  cryptomatte node  in its open source code base  please.  Surely it could provide some hint of how it can be done math wise .

 

ps. And please  make "chains" links , auto " select same color or tag'   transform links in links panel .  Whatever that would help to avoid typical situation in AP when you accidentally moved some layer or group  and your blending result or composite alpha is no more calculating right.

I wanted  to stop paying for Photoshop  but with this plugin it's so simple an convenient.  Too bad it seems not working in Affinity